Coated ceiling structure and method of forming

ABSTRACT

A ceiling system including a base ceiling structure for suspending from a structural member of a building, a substrate attached to the base ceiling structure, and a sprayable reinforcing material adhered to the substrate. The sprayable reinforcing material and the substrate together form a self-supporting composite material. A method of forming the coated ceiling structure includes the steps of providing a base ceiling structure having an outer surface, applying a foam material in a fluid state to the outer surface of the base ceiling structure, and solidifying the foam material to form a rigid reinforcing layer on the base ceiling structure. Alternatively, the base ceiling structure is a non-self-supporting material, and a reinforcing material is sprayed onto an outer surface of the base ceiling structure. The reinforcing material and the non-self-supporting material together form a self-supporting composite structure.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Application No. 60/600,597 filed on Aug. 11, 2004, currently pending, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of building construction and more particularly to a coated ceiling structure for the interior of a building and a method of forming the same.

Industrial facilities and other buildings are often exposed to air that is laden with corrosive and otherwise harmful chemicals in the form of liquids, vapors, gases and solid particulate matter. The presence of such airborne contaminants, as well as extreme temperatures and humidity, can lead to the premature wear and eventual failure ofbuilding materials, including interior ceiling structures, made from materials such as steel, wood, concrete and masonry. Many factors contribute to the deterioration of such building materials, including chemical corrosion, water absorption, condensation, mold development, loss of strength, loss of thermal insulation efficiency and the like.

Suspended or “drop” ceiling installations are well known in the building construction field. Suspended ceiling systems typically comprise a rigid grid or frame suspended from or attached to the interior surface of a roofing structure or the bottom side of a floor structure within a building. Rigid panels or tiles are then individually inserted into the openings in the grid. Each panel is supported on a ledge that extends around the perimeter of the respective opening of the grid.

Suspended ceiling panels can be made of a wide variety of materials and serve numerous purposes such as providing thermal insulation and sound absorption and improving aesthetics. Moreover, by lowering the level of the ceiling within a building, suspended ceilings effectively reduce the air volume within the building that must be heated, cooled or filtered, thereby reducing equipment costs and energy consumption. A suspended ceiling may also offer protection to building materials and structures attached to the ceiling, such as air handling and electrical equipment. However, conventional suspended ceiling systems are not capable of withstanding long term exposure to the harsh environments that exist in many commercial and industrial buildings, such as described above, without degradation and eventual failure.

BRIEF SUMMARY OF THE INVENTION

According to the present invention, a method of forming a coated ceiling structure comprises the steps of: providing a base ceiling structure having an outer surface; applying a foam material in a fluid state to the outer surface of the base ceiling structure; and solidifying the foam material to form a rigid reinforcing layer on the base ceiling structure.

According to a further aspect of the present invention, a method of forming a ceiling structure comprises the steps of: providing a base ceiling structure comprising a non-self-supporting material; and spraying a reinforcing material onto an outer surface of the base ceiling structure. The reinforcing material and the non-self-supporting material together form a self-supporting composite structure.

According to a still further aspect of the present invention, A ceiling system comprises: a base ceiling structure for suspending from a structural member of a building; a substrate attached to the base ceiling structure; and a sprayable reinforcing material adhered to the substrate. The sprayable reinforcing material and the substrate together form a self-supporting composite material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a portion of a suspended ceiling grid;

FIG. 2 is a top perspective view of a portion of a suspended ceiling structure according a first example embodiment of the present invention;

FIG. 3 is a sectional view of the suspended ceiling of FIG. 2 taken along section line 3-3;

FIG. 4 is a sectional view similar to FIG. 3 of a suspended ceiling structure according to a second example embodiment of the present invention; and

FIG. 5 is a sectional view similar to FIG. 3 of a suspended ceiling structure according to a third example embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As shown by way of example in FIGS. 1-5, the present invention provides a coated ceiling structure and a method of forming the same.

FIG. 1 shows a known ceiling frame or grid structure 10 suspended from a building structure (not shown) by a plurality of wires 12. The grid structure 10 comprises a plurality of longitudinally spaced frame members 14 connected at intervals by laterally spaced connecting members 16. In the illustrated embodiments, the frame members 14 and connecting members 16 have an inverted T-shaped cross section, as best seen in FIGS. 3-5. Other suitable shapes and configurations can be used as desired. The spacing of the frame members 14 and the connecting members 16 is selected to provide openings 18 sized to each accommodate a tile or panel 20 to be inserted therein (FIG. 2). For example, the size of the openings 18 and corresponding panels 20 may range from twelve inches by twelve inches to 48 inches by 96 inches. Other suitable dimensions can be used as determined by the requirements of the specific application.

The frame members 14 and connecting members 16 of the grid structure 10 may be made from any suitable material(s), including solid and cellular plastics, other polymers, steel, aluminum, wood, composite materials and the like. The cross-sectional dimensions of the frame members 14 and connecting members 16 are selected in accordance with strength and other requirements of a particular application. The wires 12 that suspend the grid structure 10 from the building structure may be made of any suitable material and are selected to have an appropriate strength, thickness and spacing between wires, depending upon factors such as load, regulatory requirements and other applicable requirements for a particular application.

As best shown in FIG. 2, a plurality of self-supporting panels 20 are inserted into the openings 18 in the grid structure 10 so that the peripheral edges 22 of the self-supporting panels 20 rest on surrounding ledges or flanges 24 provided by the inverted T-shaped profile of the frame members 14 and connecting members 16. As used herein, the term “self-supporting” refers to a material that is rigid, strong and/or resilient enough to withstand its own weight without deforming when the material is not supported by an additional structure. Further, as also used herein, the term “non-self-supporting” refers to materials that will substantially deform under their own weight when not supported by and/or attached to an additional supporting structure. The self-supporting panels 20 shown in FIG. 2 can be made of any suitable self-supporting material, including single or multiple layers of solid or cellular plastics, aluminum, steel, gypsum board, cement board, fiberboard, paper, cardboard, plywood, particle board, hardboard, oriented strand board, fiberglass products of various thickness, density and shapes, and other materials that meet the requirements for a particular application. Further, it should be appreciated that the grid structure 10 of the disclosed embodiments comprises frame members 14 and connecting members 16 that are self-supporting.

According to a first example embodiment of the present invention, as shown in FIGS. 2 and 3, a base ceiling structure 25 comprising the grid structure 10 and panels 20, or other suitable base ceiling structure is installed in a building structure. Then, a layer of foam material 26 is sprayed onto a substrate, namely the underside or exposed outer surface of the base ceiling structure 25. Once the foam material 26 solidifies or sets, it forms a seamless, rigid reinforcing layer. One or more additional layers of materials may be sprayed over the foam material to form a protective and/or aesthetic outer coating 28 on the foam material 26. The outer coating 28 may be used to improve the appearance of the foam material 26 and/or to provide further performance characteristics in addition to those provided to the foam material 26, depending upon the requirements of a particular installation. The foam material 26 and/or the outer coating 28 acts to strengthen or otherwise reinforce self-supporting materials such as the panels 20 of the present embodiment. The combined coated ceiling structure 30 exhibits particular desired performance characteristics including thermal insulation, moisture resistance, chemical resistance, impact resistance, washability, rigidity, strength, light weight, and the like.

By applying the foam material 26 and/or the outer coating 28, according to the present invention, it may be possible to use materials for constructing a suspended ceiling structure that would not by themselves meet strength and other engineering and/or regulatory requirements. For example, certain geographic areas, such as California, have state-mandated strength requirements for resisting seismic activity. In this example, less expensive materials that do not meet the seismic requirements could be used to construct a suspended ceiling structure, which would then be sufficiently reinforced according to the present invention to meet the seismic requirements. Other examples of regulatory requirements include national standards promulgated by the American Society for Testing Materials (ASTM), such as ASTM C 635, ASTM C 636, ASTM E 580, ASTM E 1264, which are incorporated by reference herein.

In the first example embodiment of FIGS. 2 and 3, the foam material 26 is a polyurethane foam and is sprayed onto the base ceiling structure 25 in a liquid or fluid state. Once the polyurethane foam material solidifies to form a rigid polyurethane foam insulation layer, an additional material, such as a protective topcoat of fire-resistant, unsaturated polyester liquid polymer may be sprayed or otherwise applied over the foam material 26 as the outer coating 28. Other suitable sprayable foams and other coatings may be applied to the base ceiling structure 25, depending upon the desired performance characteristics and the particular application. As used herein, “sprayable” refers to a material that can be sprayed, pumped or otherwise applied to a substrate by being dispersed in a mass or jet of droplets or droplet-like particles. Examples of sprayable materials include, for example, cellular or solid thermoset plastics and thermoplastics, other polymers, cementitious materials, fibrous materials, plaster materials, mastics, other composite materials, cellulose, commercially available sound absorbing material and insulating materials, paints, and the like. Such sprayable materials can be applied as a base coating, in place of the foam material 26, or as the outer coating 28.

Polyurethane foam is particularly suitable for spraying onto a ceiling structure according to the present invention, since it is capable of being sprayed as a foam. Once set, polyurethane foam produces a layer or membrane having a relatively high strength to weight ratio and a relatively high insulation value. However, other materials, such as intumescent paints or coatings, having suitable properties may be used according to the present invention in place of, or in addition to, polyurethane foam.

Further, the foam material 26 can vary in formulation to produce a variety of achievements. For example, the density of the foam material 26 can be varied to adjust a reaction time of the material. The term “reaction time” as used herein refers to the average amount of time it takes for a sprayed material to form a cellular foam once it is sprayed or otherwise applied to the base ceiling structure 25. By adjusting the amount of certain chemical additives in a polyurethane material, for example, the density of the resulting foam material 26 can be adjusted within a range, typically from 0.5 lb/ft³ to 3 lb/ft³ having a reaction time typically between one second and one minute, more or less. The density and reaction time of a particular material affects certain physical properties of the resulting foam material, including weight and strength.

Additionally, the contact pressure of the foam material 26 as it is sprayed onto the base ceiling structure 25 may be varied as necessary to produce a sufficiently strong and lightweight layer or membrane of foam material that solidifies or sets quickly enough. For example, the contact pressure of the foam material must be properly set to prevent the weight of the material to cause it to deform too greatly or even fall off of the base ceiling structure 25 before it can set. Contact pressure can be adjusted, as is known in the art, by varying such factors as the formula of the material, the particular equipment used to spray the material, and pressure and other settings of the spraying equipment.

The seamless nature of the spray-applied layers of the present invention, such as the foam material 26 and/or outer coating 28, provides a monolithic, aesthetically pleasing and protective membrane that protects the underlying base ceiling structure 25 from moisture, chemicals, heat, fire and/or other environmental conditions detrimental to their long term performance and use in many applications. Moreover, the spray-applied materials can add substantial strength and rigidity to the base ceiling structure 25 enabling thinner, less strong and less costly grids, panels and non self-supporting materials to be used.

In the following example embodiments of the present invention shown in FIGS. 4 and 5, to the extent that the structures illustrated therein correspond to the structures shown in FIGS. 1-3, the same reference characters will be used.

According to a second example embodiment of the present invention, FIG. 4 shows a grid structure 10 having a layer of non-self-supporting material 32 attached to the underside of the grid structure 10. The second example embodiment differs from the first example embodiment in that the self-supporting panels 20 of the first example embodiment have been eliminated. As with the first example embodiment, a foam material 26 and/or an outer coating 28, as described in detail above, is sprayed or otherwise applied onto a substrate, namely the non-self-supporting material 32. The foam material 26 adheres to the non-self-supporting material 32 such that, after the foam material 26 sets or solidifies, the combination of the non-self-supporting material 32 and the foam material 26 forms a self-supporting composite ceiling structure 33.

The non-self-supporting material 32 can be attached to the underside of the grid structure 10 by mechanical fasteners 34, such as nails, screws, bolts, brads, staples, rivets or other suitable fasteners. A continuous sheet of the non-self-supporting material 32 can be used to cover the underside of an entire grid structure 10. In this embodiment, the grid 10 and the non-self-supporting material 32 forms a base ceiling structure 25′ onto which the foam material 26 and/or other layers is applied in accordance with the present invention. Alternatively, panel-like sections (not shown) of the non-self-supporting material 32 can be used, each section covering one or more of the openings 18 in the grid structure 10. Seams between the sections of non-self-supporting material 32 are not apparent since, once the foam material 26 is applied, a seamless composite ceiling structure 33 is formed. Suitable non-self-supporting materials 32 include, for example, single or multiple layers of various materials such as heat shrinkable or non-heat shrinkable plastic films and sheets, open mesh and tightly knit fabrics, felt, wire mesh, and the like. Alternatively, the self-supporting materials described with reference to the first example embodiment and shown in FIGS. 2 and 3 can also be attached to the underside of the grid structure by the mechanical fasteners 34.

A third example embodiment of the present invention, as shown in FIG. 5, is substantially identical to the second example embodiment shown in FIG. 4, except that a layer of adhesive material 36 is used instead of the mechanical fasteners 34. In the third example embodiment, layers of the adhesive material 36, such as glue, are provided between the non-self-supporting material 32 and the grid structure 10. The adhesive material 36 can be provided on substantially all of the bottom surfaces of the grid structure that face the non-self-supporting material 32. Alternatively, the adhesive material 36 can be provided as a bead or strip and/or can be provided at spaced apart intervals, so that less adhesive material 36 is required. Other configurations of adhesive material 36 can be provided as desired.

Although the specific example embodiments of the present invention that are described herein are directed to materials that are sprayed onto a base ceiling structure 25, other suitable techniques can be used to apply the foam material 26 or other materials used to coat the underside of the base ceiling structure 25. For example, the foam material 26 or other suitable coating material could be applied on the underside of the base ceiling structure 25 by pumping or otherwise extruding the foam material 26 from a suitable nozzle or applicator so that it flows directly onto the base ceiling structure 25. Other possible methods of applying the coating material include rolling, brushing, troweling, sponging, hand rubbing/packing, air spraying, airless spraying, and other known techniques for applying coating materials.

Further, although the specific example embodiments of the present invention that are described herein are directed to applying coating materials to a suspended base ceiling structure 25 comprising a grid structure 10, the present invention contemplates the application of coating materials to other ceiling structures, including grid-less and/or non-suspended ceiling structures. As used herein, the term “non-suspended” refers to ceiling structures that are directly and/or rigidly attached to a building structure or underlying ceiling structure of a building, such that there is little or no space or gap therebetween. Further, as also used herein, the term “grid-less” refers to ceiling structures that do not include a separate supporting grid or frame to support the material to which the inventive coating(s) is/are applied. One example of a grid-less ceiling structure, not illustrated herein, comprises a plurality of interlocking tiles being suspended from or attached directly to a building structure. Another example of a grid-less ceiling structure, not illustrated herein, is a web of non-self-supporting material that is suspended under tension from surrounding wall structures. Other suitable materials and structures may be used according to the present invention.

The suspended base ceiling structure 25 described in the disclosed example embodiments are shown and described as being suspended from a building structure by a plurality of wires 12. However, other structures for suspending a base ceiling structure 25, in place of the plurality of wires 12, are contemplated to be within the scope of the present invention. Examples of alternatives to the plurality of wires 12 including metallic and nonmetallic ropes and cables, flexible or rigid strips or rods, blocks, joists, trusses, and the like.

It should be evident that this disclosure is by way of example and that various changes maybe made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. 

1. Method of forming a coated ceiling structure comprising the steps of: providing a base ceiling structure having an outer surface; applying a foam material in a fluid state to the outer surface of the base ceiling structure; and solidifying the foam material to form a rigid reinforcing layer on the base ceiling structure.
 2. The method according to claim 1, wherein the base ceilings structure comprises a non-self-supporting material, and wherein the foam material bonds to the non-self-supporting material to form a self-supporting composite structure.
 3. The method according to claim 1, wherein the foam material comprises polyurethane.
 4. The method according to claim 1, wherein the step of applying comprises spraying the foam material.
 5. The method according to claim 1, wherein the base ceiling structure comprises a self-supporting grid structure.
 6. The method according to claim 5, wherein the base ceiling structure further comprises a plurality of self-supporting panels supported in the grid structure and wherein the outer surface of the base ceiling structure comprises outer surfaces of the plurality of panels.
 7. The method according to claim 5, wherein the base ceiling structure further comprises a layer of non-self-supporting material attached to the grid structure.
 8. The method according to claim 1, further comprising the step of applying an outer coating to the rigid reinforcing layer.
 9. Method of forming a ceiling structure comprising the steps of: providing a base ceiling structure comprising a non-self-supporting material; and spraying a reinforcing material onto an outer surface of the base ceiling structure, wherein the reinforcing material and the non-self-supporting material together form a self-supporting composite structure.
 10. Method according to claim 9, wherein the reinforcing material comprises polyurethane.
 11. Method according to claim 9, wherein the reinforcing material is a foam material that is sprayed onto the base ceiling structure in a fluid state.
 12. Method according to claim 9, further comprising the step of solidifying the reinforcing material, wherein the reinforcing material bonds to the non-self-supporting material to form the self-supporting composite structure.
 13. Method according to claim 9, wherein the base ceiling structure further comprises a self-supporting frame to which the non-self-supporting material is attached.
 14. Method according to claim 12, further comprising the step of applying a protective coating to the self-supporting composite structure.
 15. A ceiling system comprising: a base ceiling structure for suspending from a structural member of a building; a substrate attached to the base ceiling structure; and a sprayable reinforcing material adhered to the substrate, wherein the sprayable reinforcing material and the substrate together form a self-supporting composite material.
 16. The ceiling system of claim 15, wherein the sprayable reinforcing material comprises a foam material.
 17. The ceiling system of claim 15, wherein the substrate comprises a non-self-supporting material.
 18. The ceiling system of claim 15, wherein the substrate comprises a plurality of self-supporting panels.
 19. The ceiling system of claim 15, wherein the sprayable reinforcing material provides a ceiling surface having a seamless appearance.
 20. The ceiling system of claim 15, further comprising a protective coating adhered to the self-supporting composite material.
 21. The ceiling system of claim 15, wherein the base ceiling structure comprises a grid structure. 